The photographic processing system that is the most commonly used for color photography is a so-called negative paper system, in which a color negative film after photographing (i.e., exposed film) is developed, and the developed image is printed on color paper in processing laboratories. Where a camera store relies on large integrated laboratories, the finishing time required from receiving an exposed film from a customer to handing over color prints to the customer has been one day. In the case of an over-the-counter development system involving no delivery from a camera store to a processing laboratory, which has recently been spreading, the finishing time is about 30 minutes to 1 hour. Processing laboratories of this type are called mini laboratories compared with large integrated laboratories. The mini laboratories have achieved a great reduction of the finishing time on behalf of customers, but the finishing time at the mini laboratories is not at all short enough for keeping customers waiting there for having their negative film finished into prints. It has been strongly desired, while very difficult to achieve, that the finishing be completed rapidly enough for leaving a customer waiting.
Development processing (from development up to drying) of a color negative film requires 10 to 15 minutes, comprising a large proportion of the total finishing time. Thus, reduction of the development processing time for color negative films has been especially demanded. There are a variety of color negative films available from film makers, and a processing laboratory undertakes any kind of the color negative films. The fact is that a laboratory develops various kinds of color negative films in one processor with one kind of each processing solution, being restricted by the cost and floor space. Therefore, the development time for color negative films is set in conformity with the film which requires the longest development time of various kinds of negative films. Color negative films requiring a long development time are frequently found among high-speed films having an ISO sensitivity of 1000 or higher. Although ISO 400 films and ISO 100 films, which are used most commonly, can be developed in a shorter time, they are developed taking the same time as assigned to those films having a higher sensitivity and a lower rate of development. That is, processing laboratories have chosen the most economical system in which different kinds of color negative films are processed in the same processor with the same processing solutions. No customer service of selecting a processing time according to the kind of the film is available. Eventually rapid development services are hardly carried out.
Techniques for correcting unevenness in product (finish) quality of development processing or photographic quality of light-sensitive materials per se through image processing have recently been proposed and put to practice use. However, when color negative films requiring a long development time are subjected to rapid processing, the deviation of the product quality from the standard level is far beyond the range of processing unevenness that could be corrected through image processing. Correction into normal image quality by image processing of films having been subjected to rapid processing and underwent much greater deviation from standard quality over the processing unevenness has not ever been thought of except for special cases.
The special cases are for restoration of old historical photographs. Attempts to restore deteriorated images are reported, e.g., in T. Rowlands, Image Technology, p. 190 (October, 1993) and Harvard University, IS & T Reporter, Vol. 8, p. 9 1993). Even in these cases, restoration is possible only when specific conditions are satisfied.
JP-B-7-52287 (the term "JP-B" as used herein means an "examined published Japanese patent application") discloses a method for developing an exposed color negative film, in which a bleaching step is omitted, and the accompanying problem that a silver image is superimposed on a color image is overcome by reading the development densities, from which the analytical densities of the image are calculated thereby to obtain the densities of the color image and those of the silver image separately. However, the resulting positive image obtained on the basis of the analytical densities of three colors, i.e., cyan, yellow and magenta, and neutral silver is still inferior in quality to the standard. There seems to be some factors deciding image quality other than analytical densities. The disclosed technique has not been put to practice yet.
Another problem of general processing laboratories mainly comprising mini laboratories is countermeasures against environmental pollution by the spent processing solutions (hereinafter called waste solutions) and drainage from a wash tank, etc. (hereinafter called waste water). Since nitrogen compounds contained in waste water are objects of drainage regulations, waste water containing nitrogen compounds increases the load of disposal. Where disposal of waste solutions is consigned, the lesser the amount of waste solutions, the lesser the cost of consignment. Therefore, a development processing system which discharges less waste solutions and drainage with reduced nitrogen components has been desired in processing laboratories. From this viewpoint, it is a thoroughly spread practice in carrying out universal development processing that waste water is reduced by a water-saving washing system (also called stabilization processing substituting for washing, inclusively designated low-throughput replenishment type washing) and waste solutions are reduced by low-throughput replenishment. However, there has been always a demand of necessity for further reductions in waste solutions and waste water.
Still another problem waiting for solution in processing laboratories mainly comprising mini laboratories is how to secure constant development quality even in the processing slack period. Because the processing throughput is smaller in the slack period, the amount of replenishers added to a processor is smaller, and the solution replacement ratio decreases. As a result, the processing solutions undergo deterioration with extension of the retention time in the processing tanks, causing, for example, sulfides and silver compounds to settle. It has therefore been demanded to take some measures for stabilizing the processing solutions in the processing tanks even in such a processing slack period.